A critical review on the interaction between calcium silicate hydrate (C-S-H) and different ions

The influence of ions, whether intrinsic to the pore solution of cementitious materials or originating from the external environment of concrete structures, exerts a considerable impact on the performance of cement-based materials. An extensive comprehension of the interactions between these ions and the primary component of cementitious materials - calcium silicate hydrate (C-S-H), stands as a fundamental prerequisite for proficiently tuning the properties and performance of concrete. This review provides a comprehensive overview of the latest studies regarding the interplay between C-S-H and different ions. The ions under considerations are broadly divided into two groups: anions and cations. For each of these anions, we critically summarize the information regarding their sources, the nature of their interactions with C-S-H, the variables influencing the interactions, and their impact on the composition, structure, and properties of C-S-H.